21621463323644 has 72 divisors (see below), whose sum is σ = 41094705220128. Its totient is φ = 9945118465920.

The previous prime is 21621463323553. The next prime is 21621463323671. The reversal of 21621463323644 is 44632336412612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 26472014 + ... + 27276554.

It is an arithmetic number, because the mean of its divisors is an integer number (570759794724).

Almost surely, 2^{21621463323644} is an apocalyptic number.

It is an amenable number.

21621463323644 is a deficient number, since it is larger than the sum of its proper divisors (19473241896484).

21621463323644 is a wasteful number, since it uses less digits than its factorization.

21621463323644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 805123 (or 805102 counting only the distinct ones).

The product of its digits is 2985984, while the sum is 47.

The spelling of 21621463323644 in words is "twenty-one trillion, six hundred twenty-one billion, four hundred sixty-three million, three hundred twenty-three thousand, six hundred forty-four".